Factors influencing degradation of DNA and hormones in maned wolf scat C. Vynne 1 , M. R. Baker 2 , Z. K. Breuer 3 & S. K. Wasser 3 1 Department of Biology, University of Washington, Seattle, WA, USA and National Fish and Wildlife Foundation, Washington, DC, USA 2 School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, USA 3 Department of Biology, University of Washington, Seattle, WA, USA Keywords Chrysocyon brachyurus; detection dog; glu- cocorticoids; noninvasive genetic sampling; sample degradation; scat; thyroid hormone. Correspondence Carly Vynne, Science and Evaluation, National Fish and Wildlife Foundation, 1133 15th Street, NW Suite 1100 Washington, DC 20005, USA Email: carly.vynne@nfwf.org Editor: David Reed Received 25 August 2011; accepted 3 October 2011 doi:10.1111/j.1469-1795.2011.00503.x Abstract The ability to noninvasively detect the presence of species and assess physiological health by DNA and hormone analysis makes scat a valuable tool for ecology and conservation. We assessed factors associated with DNA and hormone degrada- tion in a four-season study that employed detection dogs to collect scats from maned wolf (Chrysocyon brachyurus) in the Brazilian Cerrado, a tropical savanna landscape mosaic. Fecal DNA sample viability was assessed by attempting polymerase chain reaction amplification of a mitochondrial DNA (mtDNA) locus (~ 246 bp) and a nuclear DNA zinc finger protein gene (~ 195 bp). We assessed how extraction method, environmental exposure, and amount of odor, moisture and diet items in the sample influenced DNA amplification and allelic dropout rates. Samples that amplified mtDNA were assayed for glucocorticoids and thyroid hormone. Amount of odor and moisture (indicating freshness) predicted mtDNA amplification success, as well as mean hormone levels. While factors related to sample condition were negatively correlated with lower mean hormone levels, samples comprised mainly of fruit had higher levels of glucocorticoids and lower levels of thyroid hormone, and we thus interpret this result as biologically meaningful. In summary, DNA and hormone degradation are predicted by meas- ures of sample freshness, making the assessment of sample quality an important criterion for sample collection as well to manage measurement error in analyses of hormone concentration associated with environmental disturbance. Introduction The advent of improved efficiency in molecular methods makes the use of noninvasively collected samples increas- ingly feasible for presence–absence, demographic, hybridi- zation and physiological studies (Foran, Crooks & Minta, 1997; Wasser et al., 2004; Adams, Lucash & Waits, 2007; Ball et al., 2007). Noninvasive genetic sampling has been extremely useful for identifying species and individuals in an area, evaluating distribution, determining sex ratio and esti- mating population size (Kohn et al., 1999; Bellemain et al., 2005; Waits & Paetkau, 2005; Solberg et al., 2006), and fecal hormone metabolites may be used to assess physiological health and the disturbance response of populations (Creel et al., 2002; Rolland et al., 2006; Gobush, Mutayoba & Wasser, 2008). Scat is particularly enticing for studies of species of conservation concern because it may be collected noninvasively, without having to capture, handle or observe animals. When scats are subject to DNA and/or hormone extraction and analysis, however, poor sample quality can increase measurement error, wasting laboratory costs on extraction and amplification of degraded DNA or hor- mones. Degradation of hormones in samples is particularly problematic since these are quantitative measures and thus necessitate the removal of variation in hormone levels due to degradation from that resulting from disturbance variables of interest (e.g. noise, habitat degradation). Factors that influence sample quality can be considered to minimize effort collecting and analyzing samples unlikely to yield high-quality DNA, as well as to account for variation due to sample condition when analyzing sample hormone levels. Variables influencing condition of samples in the field have been shown to influence DNA amplification success and include age of sample (Lucchini et al., 2002; Piggott, 2004; Santini et al., 2007), weather conditions (Farrell, Roman & Sunquist, 2000; Lucchini et al., 2002; Piggott, 2004), diet (Murphy, Waits & Kendall, 2003; Maudet et al., 2004) and intestinal slough rate, which may vary among species and within species as diets vary by individual or season (Farrell et al., 2000; Maudet et al., 2004). These studies have suggested that success rates will be highest when samples are as fresh as possible and climatic condi- Animal Conservation. Print ISSN 1367-9430 184 Animal Conservation 15 (2012) 184–194 © 2011 The Authors. Animal Conservation © 2011 The Zoological Society of London